<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
			var s = "hello";
			var n = 3.14;
			var b = true;
			console.log('1'+'1');
			console.log('1'-'1');
			console.log('1'*'1');
			console.log('1'/'1');
			console.log('****************');
			console.log(typeof("abc"));
			console.log(typeof(123));
			console.log('****************');
			console.log(isNaN(s));//判断变量是否为数字
			console.log(isNaN(n));
			console.log(isNaN(b));
			console.log('****************');
			console.log(5/2);
			console.log('1'==1);//比较值
			console.log('1'===1);//比较类型和值
			console.log('****************');
			var x = false;
			console.log(x ? 1 : 0);//空为false
			var y = 1;
			console.log(y ? 1 : 0);//非空都为true
			
		</script>
	</body>
</html>